Apparatus for testing separable magnetic cores at varying positions to one another

ABSTRACT

A closable test fixture for paired ferrite cores includes (1) a test coil supported within the fixture and connected to terminals accessible from without the fixture, (2) a spring-loaded pad and (3) a rotatable pad having a shaft accessible from without the fixture. Automatically operated facilities are provided for: (1) loading a pair of ferrite core halves within the fixture in axially spaced relationship on opposite sides of the coil; (2) closing and latching the fixture to assemble the core halves and enclose the test coil therein, holding the core halves together with a predetermined, constant pressure between the two pads; (3) conveying the fixture to successive testing stations where contact is made with the access terminals on the fixture and a driver is actuated to rotate the pad and one core half 360* with respect to the other to produce a range of test results; and (4) conveying the fixture to a vibratory swing nest which is actuable to unlatch and open the fixture to release the core halves into a chute for paired packaging.

United States Patent [72] Inventors Allen N. Martin;

John L. Speas, both of Winston-Salem, I\'.C.

[21] Appl. No 861,572

[22] Filed Sept. 29, 1969 [45] Patented Oct. 19, 1971 [73] AssigneeWestern Electric Company, Incorporated,

New York, N.Y.

[54] APPARATUS FOR TESTING SEPARABLE MAGNETIC CORES AT VARYING POSITIONSTO Primary Examiner-Rudolph V. Rolinec Assistant Examiner-R. J1 CorcoranAttorneys--W. L. Williamson, W. M, Kain, R. P, Miller and B.

I. Levine ABSTRACT: A closable test fixture for paired ferrite coresincludes (l) a ten coil supported within the fixture and connected totennilals accessible from without the fixture, (2) a spring-loaded padand (3) a rotatable pad having a shaft accessible from without thefixture. Automatically operated facilities are provided for: (1) loadinga pair of ferrite core halves within the fixture in axially spacedrelationship on opposite sides of the coil; 2) closing and latching thefixture to assemble the core halves and enclose the test coil therein,holding the core halves together with a predetermined, constant pressurebetween the two pads; 3) conveying the fixture to successive testingstations where contact is made with the access tenninals on the fixtureand a driver is actuated to rotate the pad and one core half 360 withrespect to the other to produce a range of test results; and (4)conveying the fixture to a vibratory swing nest which is actuable tounlatch and open the fixture to release the core halves into a chute forpaired packaging.

SHEET 2 OF PATENTED 19 3.614.603 SHEET 5 BF 6 APPARATUS FOR TESTINGSEPARABLE MAGNETIC CORES AT VARYING POSITIONS TO ONE ANOTHER BACKGROUNDOF THE INVENTION 1. Field of the Invention The invention relates to anapparatus for testing separable magnetic cores at varying positions toone another and more particularly to an automatic apparatus for handlingmagnetic cores before, during and atter testing thereof.

2. Technical Considerations Inductor devices and other magnetic circuitcomponents have, for some time, utilized the unique advantages offerrite materials. Ferrites exhibit several characteristics, such ashigh relative permeability, high resistivity and low core loss, whichare extremely useful in magnetic circuits. Ferrite cores for inductors,for instance, have been utilized extensively in audio and high-frequencyequipment, such as telecommunications equipment and the like.

Ferrite cores are molded from mixtures of metallic oxide powders and areusually extremely brittle. Thus, they are highly susceptible tochipping, scratches and other injury when care is not taken in handlingthem during subsequent operations such as testing and final assemblyinto circuit components. It has furthermore been found that ferrite dustcreated by the rubbing together of ferrite cores and from chips andother broken ofi ferrite particles, is highly abrasive and tends toaccelerate wear on various automatic article handling mechanisms such asgrippers and conveyors. Aside from the physical damage to ferrite coresarising from excessive handling, it has further been found thatmechanical shocks imparted to molded ferrite materials during handlingmay result in the undesirable alteration of their magneticcharacteristics as well.

In one type of ferrite core inductor, ferrite cores in the shape ofhollow toroids are separable into two parts, each part constituting onecore half. The core halves are assembled and so fitted together as tocompletely enclose a bobbin wound inductor coil to provide both an axialmagnetic path through the center of the coil and a coaxial magnetic pathexternal to the coil. The testing of the magnetic characteristics of amagnetic core for the foregoing inductor comprises the testing of pairedcore halves as a unit. It is therefore necessary, in order to testpaired magnetic core halves, to: (l) assemble the core halves over atest coil, holding the core halves assembled with a predetermined,constant, contact pressure; 2) provide an electrical connection betweenthe enclosed test coil and the test equipment; (3) rotate the coresrelative to each other about their common axis to obtain a range of testresults arising from the changed relative rotational positioning of thecore halves; and (4) disassemble the core halves after the test resultsare obtained.

lf several tests are to be carried out on these magnetic cores, theabove steps must be repeated for each test. Manual execution of theseprocedures for large numbers of mass produced magnetic cores is costlyboth from the standpoint of the time consumed as well as the risk ofinjury to the magnetic cores involved in successively assembling anddisassembling the cores.

it would be an advantage to avoid successive assembling anddisassembling of paired ferrite cores where multiple tests are to beperformed thereon in order to reduce the risk of injury to the cores dueto excessive handling subsequent to fabrication.

lt would be a further advantage to provide an apparatus which couldfacilitate the automatic performance of a series of tests on pairedmagnetic cores by reducing the assembly and.

disassembly operations on each core to a single instance each such thata core may be assembled, completely tested and disassembled.

SUMMARY OF THE INVENTION An object of the present invention is toprovide new and improved apparatus for facilitating testing of magneticcores by minimizing handling of the cores before, during and aftertesting thereof.

Another object of the present invention is to provide new and improvedapparatus for facilitating multiple testing of magnetic core halves as aunit by assembling the core halves in operative relation to a testfacility and transporting the assembled core halves and the testfacility to successive testing stations where test connections may bemade to the test facility.

An additional object of the present invention is to provide a new andimproved test fixture for receiving and supporting the separable halvesof a magnetic core in operative relation with a test coil supportedwithin the fixture and being accessible from without the fixture.

A further object of the present invention is to provide a transportabletest fixture for magnetic cores which fixture is adapted to receive andprovide testing access to magnetic cores and to protect the receivedcores from mechanical shock during testing thereof.

A still further object of the present invention is to provide a new andimproved apparatus for facilitating testing of magnetic cores includinga test fixture which may be automatically loaded with magnetic cores andthereafter conveyed to suecessive test stations where the cores may beadjusted relative to each other during testing thereof and subsequentlyunloaded.

With these and other objects in view, the present invention contemplatesa new and improved test apparatus for separable magnetic cores includinga portable test fixture for receiving the separable parts of the coresfor operative association of the core parts with a test facilitysupported within the fixture and accessible from without the fixture,together with an instrumentality for varying the operative associationof the separable parts of the core to render available a range of ,testresults.

The test facility is a standard test coil supported within the fixture.Paired ferrite core halves are retained within the fixture in anassembled condition with a predetermined, constant pressure. Loading ofthe fixture is automatic and the loaded fixture is thereaftertransported on a conveyor to: l a closing station at which anautomatically operated closure operator closes and locks the fixture;(2) one or more test stations at which test connections are made to thecoil and an adjusting member is actuated to rotate one core half withrespect to the other in order to produce a range of test results; and 3)an unloading station where the fixture is conveyed into a swing nestwhich is actuated to unlock and open the fixture to release the testedcore halves into a chute for packaging or the like.

BRIEF DESCRIPTION OF THE DRAWINGS A comprehensive understanding of theinvention will be obtained by considering the following several views ofthe drawings in conjunction with the detailed description, wherein:

FIG. 1 shows a ferrite core inductor comprising two cupshaped ferritecore halves assembled to enclose a bobbinwound inductor coil;

FIG. 2 is a sectional view of the ferrite core inductor taken along theline 2-2 of FIG. 1;

FIG. 3 is an exploded view of the test fixture of the invention forfacilitating testing of paired cup-shaped ferrite cores;

FIG. 4 is a perspective view of the test fixture of FIG. 3 after it hasbeen loaded with paired ferrite cores, closed and latched;

FIG. 5 is a sectional view of the closed test fixture, taken along theline 5-5 of H6. 4, showing the latches for retaining the test fixtureclosed and a phantom line representation of the operative positions ofthe fixture latches for opening the fixture;

FIG. 6 is a perspective view of a loading station for loading pairedferrite cores into the test fixture of FIG. 1, a closing station forclosing and latching the loaded fixture and a testing and adjustingstation for making test contact with and imparting relative rotation tothe ferrite cores within the fixture, together with apparatus forconveying empty fixtures to the loading station and for conveying theloaded fixtures to the closing station and testing station;

FIG. 7 is a front view of the test fixture of FIG. 4, partly in section,also showing the positioning of a core adjusting member for rotating onecore half in the fixture 360 with respect to the other;

FIG. 8 is a schematic diagram of the electrical circuit for controllingthe operation of the loading, closing and adjusting apparatus of FIG. 6;

FIG. 9 is a schematic diagram of the pneumatic system for operating theloading, closing and adjusting apparatus of FIG.

FIG. 10 is a perspective view of an apparatus for unloading the testfixture after testing has been completed;

FIG. 11 is a front elevational view, partly in section, of an unloadingnest for receiving and unlatching the test fixture to separate themagnetic cores therefrom;

FIG. 11A is a enlarged sectional view, taken along the line A-A of FIG.11, showing an air rotator shaft, having a cam slot formed therein forcooperating with a pin and stud in the unloader nest in order to impartan initial 45 counterclockwise rotation thereto in order to aid infreeing the magnetic cores from the fixture;

FIG. 11B is a enlarged sectional view, similar to FIG. 11A and takenalong the line B-B of FIG. 11, showing a second shaft, pin and studarrangement for imparting successive 90 clockwise and 45counterclockwise rotational movements to the unloader nest, to furtheraid in freeing the cores and return the unloader nest to its originalposition;

FIG. 12 is a side elevational view of the unloading nest of FIG. 10showing a phantom representation of the nest tilted to dump the unloadedcores from the test fixture in the nest into a discharge chute;

FIG. 13 is a schematic diagram of the electrical circuit for controllingthe operation of the unloading apparatus of FIGS. 10 and 11;

FIG. 14 is a schematic diagram of the pneumatic system for operating theunloading apparatus of FIGS. 10 and 11; and

FIG. 15 is a cam timing diagram showing the sequence of operations ofselected ones of the several component mechanisms of the unloadingapparatus of FIGS. 10 and 1 1.

DETAILED DESCRIPTION Referring to FIGS. 1 and 2, there is shown aninductor device including a magnetic core comprising a pair of cupshapedferrite core halves 21 and 22 which are assembled to enclose an inductorcoil 23 wound on a bobbin 24. Each of the core halves 21 and 22 isformed with internal cylindrical projections 26 and 27, respectively,which, when the core halves are assembled, extend from opposite sidesthrough the center of the bobbin 24 to form a magnetic path coaxial withthe coil 23. The core half 21 is truncated at its extremities fonningwindows or apertures 28-28 on opposite sides thereof to permit a pair ofleads 29-29 from the coil 23 to be connected to an external circuit.

FIGS. 3 and 4 shown a test fixture 31 for holding together two ferritecup-shaped core halves 21 and 22 with a predetermined, constant pressureover a test coil 32 wound on a bobbin 33 while the fixture is conveyedthrough various testing stations. While the contact pressure between thecore halves is maintained, one core half may be rotated 360 with respectto the other within the fixture 31 to produce a range of results duringtesting.

The fixture 31 includes a U-shaped end plate 34 and a rectangular endplate 36 both of which are slidably mounted for movement toward and awayfrom a central block 37 on four parallel guide rods 3838. The guide rods38-38 extend through eight apertures 39-39 formed in a pair ofoppositely disposed bifurcated arms 41 and 42 on the central block 37.Two of the guide rods 3838 extend from diagonally opposite apertures39-39 through a pair of aligned apertures 43-43 in end plate 36.Similarly, the remaining two guide rods 3838 extend from diagonallydisposed apertures 39-39 through a pair of aligned apertures 44-44 inend plate 34.

The end plates 34 and 36 are normally urged away from the central block37 by four helical compression springs 46-46 each surrounding one guiderod 38. Movement of the end plates 34 and 36 away from central block 37is limited by snap rings 47-47 which engage outer ones of four spacedgrooves 48-48 in each of the guide rods 3838 and the offset portions49-49 of counterbores or the like which may be formed around the variousaligned apertures.

The end plate 34 has formed therein a counterbored opening 51 forreceiving a stub shaft 52 surrounded by a compression spring 53 andattached to a truncated circular retaining pad 54. The shaft 52 and thepad 54 attached thereto are retained within the opening 51 against theaction of spring 53 by snapring 56 which engages the offset portion ofopening 51 and a groove 57 formed in the shaft 52. The spring 53 iscalibrated to urge the pad 54 toward the opening between the arms 41 and42 of the central block 37 with a predetermined force.

The end plate 36 is formed with a counterbored opening 58 for receivinga bored shaft 59 connected to a similarly bored rotatable pad 61 whichhas adhesively secured thereto a resilient annulus 62 made of rubber orthe like. The shaft 59 is rotatably retained in the opening 58 by asnapring 60 which engages an offset 63 formed in the counterboredopening 58 and a groove 64 formed in the shaft 59. The end of shaft 59is formed with a slot 65 to receive a rotatable adjusting member 66(FIGS. 6 and 7) which may be driven to rotate the pad 61. The pads 54and 61 are axially aligned with one another within the space defined bythe arms 41 and 42 of the central block 37.

Secured to the rear wall of the block 37 by a pair of screws 67-67 is aU-shaped bobbin support 68 attached to which is the bobbin or spool 33upon which is wound the test coil 32. The support 68 and the bobbin 33may be a unitary structure fabricated from nylon or the like. A pair oftest leads 71-71 from the coil 32 are retained within a pair of lateralgrooves 72-72 formed in the bobbin support 68 and are connected to apair of access terminals 73-73 supported within the arm 41 of the block37. The core halves 21 and 22 may be assembled over the bobbin 33 tocompletely enclose the test coil 32 in the same manner as shown in FIG.2 where the cores 21 and 22 enclose inductor coil 23 wound on bobbin 24.

The spaces between the bifurcations of the arms 41 and 42 of centralblock 37 are adapted to receive a pair of latches 74-74 which arepivotally mounted on pivot pins 76-76 which extend across thebifurcations of arms 41 and 42. As seen more clearly in FIG. 5 eachlatch 74 is formed with two semicircular cutout portions 77 and 78 whichare normally urged into the inner spaced grooves 48-48 in opposite pairsof guide rods 38-38 by the force provided by a tension spring 79 whenthe fixture 31 is closed as shown in FIGS. 4 and 7. The tension spring79 connects the latches 74-74 to each other and retains the fixture 31in its closed position until a projecting portion 80 on each latch 74 isdepressed to pivot the latch 74 about pin 76 against the force of spring79. Depression of projections 80-80 moves the semicircular cutouts 77-77and 78-78 out of engagement with grooves 48-48 in rods 3838 to pennitthe springs 46-46 to move the end plates 34 and 36 away from centralblock 37. The bifurcated arms 41 and 42 are fonned with centrallyextending slots 81-81 into which an unlatching member may be moved todepress projections 80-80. The slots 81-81 also serve to protect thefixture from being unlatched by its own weight while resting on a fiatsurface since the projections 80-80 do not, by virtue thereof, extendoutward of the fixture 31.

The fixture 31 may be loaded with a ferrite core pair 21 and 22 byunlatching the latches 74-74 to permit springs 46-46 to urge the endplates 34 and 36 away from the central block 37. The flat sided corehalf 21 may then be inserted between the anus of a U-shaped bobbinsupport 68, the projection 26 of core half 21 then being aligned withthe axis of bobbin 33 while the outer walls of the core half 21 extendover the bobbin 33. The circular core half 22 may then be insertedbetween rotatable pad 61 and the bobbin 33 to align the projection 27 ofcore half 22 with the axis of bobbin 33 and the projection 26 ofinserted core half 21. The outer wall of core half 22 will thus extendover the bobbin 33. The fixture 31 may then be closed by moving the endplates 34 and 36 toward the central block 37 against the urging ofsprings 46-46 until the semicircular cutouts 77-77 and 78-78 of latches74-74 engage the grooves 48-48 of guide rods 38-38 to lock the fixtureclosed. it is seen that once the fixture 31 is closed it isself-latching.

When the fixture 31 is closed and latched, the core halves 21 and 22completely enclose and capture the bobbin 33 and the test coil 32 woundtherearound. The core halves 21 and 22 are held together with a constantpressure exerted by the calibrated spring 53 against core halves 21 and22 and pad 61. This pressure is independent of the forces exertedagainst end plates 34 and 36 by the springs 46-46 while the fixture 31is closed. If the shaft 59 is rotated, while the fixture 31 is closed,the frictional forces between the resilient annulus 62 and the core half22 will then act to rotate core half 22 with respect to core half 21since the core half 21 will be prevented from rotating by the bobbinsupport 68. Test connections may be made to thecontact tenninals 73-73in arm 41 of central block 37. The construction of the fixture 31 issuch that the core halves 21 and 22 are centered and aligned with eachother upon their insertion into the fixture.

Since magnetic core tests are frequently carried out on a mass basis,facilities have been provided for automatically loading, closing,adjusting and unloading the fixture 31 during testing of the core halves21 and 22 therein.

FIG. 6 shows an apparatus for l) conveying a test fixture to a loadingposition, (2) loading the fixture with paired ferrite cores, (3) closingthe fixture and (4) making test contact with the test coil in thefixture while rotating the circular core half 22 360 with respect to theflat-sided core half 21.

A fixture carrying conveyor belt 82, in a guideway defined by a pair ofend plates 83-83, is driven by a motor 84 through a gear box 86. Thebelt 82 is reversed just short of a guide wall 87 which houses amicroswitch 88. As shown in FIG. 8, the microswitch 88 is normally openand is in series with a relay 89.

Adjacent to the guide wall 87 is an air cylinder 91 having a piston 92on the end of which is a pusher pad 93 for engaging a fixture 31 on theconveyor 82 and in contact with microswitch 88. The air cylinder 91 iscontrolled by a valve 94 (FIG. 9) actuated by a solenoid 96 to feed airfrom an air supply 97 through a valve 98 actuated by a solenoid 99. Theair cylinder 91 may be operated to push an open fixture 31 along thewall 87 into a trackway 100 until the fixture abuts a wall 101 to alignthe fixture 31 with a pair of loading trackways 102 and 103. I

The trackways 102 and 103 are adapted to receive core halves 21 and 22,respectively, which may be loaded thereon and moved therealong by a pairof fingers 104 and 106 on a pair of conveyor chains 107 and 108,respectively, driven by a motor 109 (FIG. 8). A pair of normally openmicroswitches 111 and 112, disposed above the trackways 102 and 103,respectively, are positioned to be actuated by core halves 21 and 22 asthey are moved. As seen in FIG. 8, microswitches 1 1 1 and 112 areconnected in series with solenoid 96.

The chains 107 and 108 extend beneath slots 113 and 114 in a fixturetrackway 115 aligned with trackways 102 and 103. The trackway 115extends through a fixture closing station 116 and a testing and coreadjusting station 117.

The fixture closing station 116 includes a horizontal supporting member118 to which is fixed a fixture detecting microswitch 119. Thehorizontal support member 118 is supported at either end by a pair ofsupport plates 121 and 122 which also support two fixture-closing aircylinders 123 and 124, respectively. The air cylinders 123 and 124 areconnected to be operated simultaneously through a valve 126 (FIG. 9)under the control of a solenoid 127. As shown in FIG. 8, thefixture-detecting microswitch l 19 and the solenoid 127 are connected inseries with a timed relay 128. When air cylinders 123 and 124 areoperated, they move respective pistons 129 and 131 toward each other. Ifan open fixture 31 is on the trackway between the support plates 121 and122, pads 132 and 133 on pistons 129 and 131, respectively, will act toclose and latch the fixture 31. A centering rod 134 on pad 133 isadapted to enter the fixture 31 through the bore in shaft 59 to insurecentering of the loaded cores 21 and 22.

The testing and adjusting station 117 includes a normally openmicroswitch 136 which may be closed by a moving closed fixture on thetrackway 1 15, which may be narrowed in the vicinity of station 117 toguide fixture 31 therein. An L- shaped support member 137 supports acontact box 138 from which protrudes a pair of test contacts 139-139adapted to make a test connection to the access terminals 73-73 on thefixture 31 in order to perfonn one or more tests on the cores 2! and 22in the fixture 31. A guide rod support 141 supports a pair of guide rods142-142 and an air cylinder 143 having a piston 144 connected to a motorsupport 146, slidably mounted on guide rods 142-142. The air cylinder143 is operated through a valve 147 (FlG. 9) actuated by a solenoid 148,in series with the microswitch 136 (FIG. 8) and a relay 149, to move themotor support 146 and a drive motor 151 mounted thereon toward thefixture 31 on the trackway 115 at station 1 17. The motor 151 may beactuated to rotate the driving member 66 as the motor 151 moves towardthe fixture 31 until a rod 152 (FIG. 7) on the driving member 66 entersthe bore in shaft 59 on the fixture 31 to guide a head 153 and drivingmember 66 into the slot 65 formed in shaft 59 (FIG. 7). As shown in FIG.7, the core half 22 may then be rotated with respect to the core half 21while the test is being conducted thereon to vary the magneticcharacteristics thereof in order to obtain a range of test results.

The sequence of operation of the various parts of the loading, closingand adjusting apparatus of FIG. 6 can best be understood by referring tothe electrical circuit diagram of FIG. 8, considered in conjunction withthe pneumatic diagram of FIG. 9. In the circuit diagram relay contactsare represented by detached contacts, crosses (X"s) indicating make" ornormally open contacts and bars (Is) indicating break" or normallyclosed contacts. The contact pair associated with a designated relay isnumbered the same as the relay with a lower case letter following thenumber to indicate a particular contact pair.

The operation of the loading, closing and adjusting apparatus is asfollows. A pair of ferrite core halves 21 and 22 are placed in trackways102 and 103, respectively, either by an operator or by an automaticfeeding apparatus which may be a modification of the automatic apparatusdisclosed in application Ser. No. 862,235 entitled Apparatus ForAssembling Pieceparts Into Cup-Shaped Adapters," filed Sept. 30, 1969 inthe name of E. H. Craver and assigned to the assignee of the presentinvention. One or more open fixtures 31 may be placed on the conveyorbelt 82 with its access terminals 73- 73 upward and its end plate 36facing the trackways 102 and 103. The operator may then close a startswitch 153 to energize a relay 154 through a normally closed stop switch156 from a source 157 which supplies 24 V DC to the system. Energizationof relay 154 closes contacts 154a through 154d. Closure of contacts 154aholds relay 154 energized while closure of contacts 154b energizessolenoid 99 which actuates valve 98 to supply air from air supply 97 tothe pneumatic system of FIG. 9. Closure of contacts 1540 energizes thechain drive motor 109 through normally closed contacts 128a and 149a ofrelays 128 and 149, respectively. Closure of contacts 154d sets up relay89 which will then be energized upon closure of microswitch 88.

Conveyor motor 84 is energized through normally closed contacts 89a ofrelay 89 to move a fixture 31 into contact with microswitch 88 in guidewall 87 (FIG. 6). When microswitch 88 is closed, relay 89 is energizedto open contact 89a and stop the conveyor belt drive motor 84 to stopthe conveyor belt 82 with a fixture 31 in line with piston 92 of aircylinder 91.

As the core halves 21 and 22 are moved along trackways 102 and 103 byfingers 104 and 106 on driven chains 107 and 108, they close normallyopen microswitches 111 and 112 over trackways 102 and 103 to energizesolenoid 96. The energization of solenoid 96 actuates valve 94 whichoperates air cylinder 91 to move piston 92 and pusher pad 93 to push afixture 31 into alignment with trackways 102 and 103 to receive thecores 21 and 22 therefrom.

The fingers 104 and 106 push the cores 21 and 22 into the alignedfixture 31 and continue moving to carry the fixture along trackway 115to the closing station 116. As the fixture 31 is moved ofi the belt bythe pusher pad 93 on piston 92, microswitch 88 is opened to deenergizerelay 89 which may be timed to allow contacts 890 to close and restartconveyor motor 84 after providing sufficient time for the piston 92 toretract back into the air cylinder 91 when solenoid 96 is deenergizedupon the opening of microswitches 111 and 112 when core halves 21 and 22have passed therefrom on trackways 102 and 103.

As the fixture 31 approaches the closing station 116, microswitch 119 isclosed to energize relay 128 and solenoid 127. Energization of relay 128opens normally closed contacts 128a to stop chain drive motor 109 tostop the fixture 31 on the trackway 115 at the closing station 116.Energization of solenoid 127 actuates valve 126 to operate air cylinders123 and 124 to move pistons 129 and 131 toward the center of trackway115 whereupon pusher pads 132 and 133 act to close and latch the fixture31 to capture the bobbin 33 and coil 32 wound therearound centering rod134 on the pad 133 enters the fixture 31 through the base in shaft 59 toassure centering of the core halves 21 and 22 along the axis of coil 32.The relay 128 is timed to reclose contacts 128a after a predeterminedinterval to restart the chain drive motor 109 and to deenergize solenoid127 to retract pistons 129 and 131 of air cylinders 123 and 124,respectively.

When the chain drive motor 109 is started again, the now closed fixture31 is carried further along trackway 115 to testing and adjustingstation 117. As the fixture 31 approaches the station 117, microswitch136 is closed to energize relay 149 and solenoid 148. Energization ofrelay 149 opens contacts 14911 for a predetermined time to stop thechain drive motor 109 to stop the fixture 31 at station 117. At thistime, testing access to coil 32 is accomplished through contacts 139-139and access tenninals 73-73 of fixture 31. At the same time, contacts149!) of timed relay 149 close to energize the motor 151 to rotate coreadjusting member 66.

Energization of solenoid 148 actuates valve 147 to operated piston 143to slide motor support 146 and motor 151 thereon toward the fixture 31.The adjusting member 66 is passed through an aperture 154 on the support137 and the guide rod 152 enters the bored shaft 59 (FIG. 7) to guidethe head 153 into the slot 65 formed in shaft 59 to rotate the shaft 59and thus rotate core half 22 to obtain a range of test results. Theadjusting member 66 may be spring-loaded as shown in FIG. 7 to assurethat head 153 enters the slotted shaft 59. When the solenoid 148deenergizes, the valve 147 operates the air cylinder 143 to retract themotor support 146. At this time, contacts of timed relay 149 close tostart chain drive motor 109 to carry the closed fixture to subsequenttesting stations which may be similar to station 117.

After testing of the core halves has been completed, the fixture istransferred to an unloading station where it is unlatched, opened andthe cores emptied into a chute for packaging or the like.

Referring to FIGS. 10, 11, 11A, 11B and 12, an unloader 156 includes aninput track 157, a transfer track 158, a swing nest 159 and a dischargechute 161. The input track 157 includes a pair of side rails 162- 162for guiding a test fixture 31 arriving from a final testing station. Thefixture 31 may be conveyed onto the input track 157 by a chain conveyorsimilar to the chains 107 and 108 or it may be pushed therein by apusher arm or" track 157 may be inclined to gravity-feed the fixturetoward the transfer track 158. A microswitch 163 is disposed in thetrack 157 such that it will be closed when it is contacted by a movingfixture 31 in the track 157.

The transfer track 158 is slotted to receive a transfer pin 164 mountedon a slide 166 connected to a piston 167 in an air cylinder 168. Theslide 166 moves along a pair of guide rods 169-169 supported at one endon a plate 171 secured to a base frame 172 and at the other end in apair of support brackets 173-173 also secured to frame 172.

The air cylinder 168 is operated through a valve 174 controlled by asolenoid 176 (FIG. 14). The air cylinder 168 may be operated to move thepiston 167 and the slide 166 to bring the transfer pin 164 intoengagement with a closed fixture 31 on transfer track 158 to move thefixture 31 along track 158 into a rotatable receiver 177 in swing nest159. The receiver 177 may be rotated in the direction of the arrow shownin FIG. 10 by an air-operated rotator 178 through a rotatable arm 179and a link 181 connected by a pin 182 to a projection 183 on a guideway184 extending from receiver 177.

If the fixture 31 is loaded into receiver 177 with the access terminals73-73 upward and end plate 34 leading, the latches 74-74 will be alignedwith a pair of spring-loaded unlatching members 186-186 (FIG. 11) havingcamming ends 187- 187 adapted to ride in a cam trackway 188 formedwithin the swing nest 159. When the arm 179 is rotated 90 in thedirection shown in FIG. 11, an opening 189 in receiver 177 will bealigned with a passageway 191 in the swing nest 159 disposed above thedischarge chute 161. As the receiver 177 is rotated, the unlatchingmembers 186-186 will be cammed by the trackway 188 into engagement withlatches 74-74 to spring the fixture 31 open to free the core halves 21and 22 so that they will pass out of the fixture 31 through opening 189and passageway 191 into the discharge chute 161.

To insure unloading of the core halves 21 and 22 from the fixture 31,means are provided for applying vibrations to the swing nest 159 and fortilting the swing nest 45 in two opposite directions with respect to thehorizontal plane of the frame base 172 to free any core half which maybe hung up on bobbin 33 or otherwise remaining in the fixture 31.

A vibrator 192, driven by a vibrator control 193 (FIG. 13), ismechanically connected to swing nest 159 through a bracket 194. Thevibrator 192 aids in freeing the core halves 21 and 22 from the now openfixture 31. A pair of airoperated rotators 196 and 197 may be operatedin sequence to rotate the nest 159 first counterclockwise until itreaches a 45 angle with respect to the horizontal direction, and then 90counterclockwise with respect to FIGS. 10 and 12 until it reaches a 45angle with respect to the horizontal plane of base 172 thus insuring thefreeing of the cores from the fixture 31 and the releasing of them intothe discharge chute 161.

The air-operated rotators 178, 196 and 197 may be identical devices ofthe well-known type wherein the introduction of air into the rotatorcauses a rotatable shaft thereon to rotate 90 in a given direction. Asshown in FIGS. 11A and 118, the air rotators 196 and 197 include hollowoutput shafts 198 and 199, respectively, adapted for insertion into apair of cylindrical hollows 200 and 201, respectively, in swing nest 159over a pair of studs 202 and 203 formed within hollows 200 and 201,respectively. The ends of shafts 198 and 199 are formed with cam slots204 and 205, respectively, which extend 45 circumferentially around eachshaft 198 and 199. A pair of pins 206 and 207 inserted within the swingnest 159 ride in the slots 204 and 205 and act to pivot the swing nestabout an axis L-L through the studs 202 and 203 when pins 206 and 207are engaged by the positively driven rotator shafts 198 and 199,respectively.

The sequence of operation of the various parts of the unloader apparatusof FIGS. 10, 11 and 12 can best be understood by referring to theelectrical control circuit diagram of FIG. 13 considered in conjunctionwith the pneumatic diagram of FIG. 14 and the cam position diagram ofFIG. 15.

The initiation and stopping of the unloader 156 is controlled by anon-off switch 208 and the microswitch 163 at the input track 157. Allswitches are shown in their normal positions before initiation of theunloading cycle. Operating potential is supplied by a I 15 V AC source209 through switch 208. When switch 208 is closed, a solenoid 211 isenergized to actuate a valve 212 to supply air to the pneumatic systemfrom an air supply 213.

As the closed fixture 31 emerges from the last testing station andenters input track 157, the moving fixture closes microswitch 163 toenergize a motor 214 which drives a plurality of cams 216 to 222 (FIG.13) which operate a like plurality of associated cam switches 223 and229. The camming arrangement thus described controls the operation ofthe transfer air cylinder 168 and the air rotators 178, 196 and 197.

Cam Switches 224 and 225 are closed by cams 217 and 218, respectively.Closure of cam switch 224 activates a DC power supply 231 while closureof cam switch 225 sets up a relay 232 through an open microswitch 233.Thereafter cam switch 226 is closed by cam 219 to energize solenoid 176which actuates valve 174 to operate the air cylinder 168, moving piston167 and transfer pin 164 into the transfer track 158 to engage and movefixture 31 toward the swing nest 159 to load the fixture 31 intorotatable receiver 177.

As the piston 167 moves toward swing nest 159, the slide 166 closesmicroswitch 233 to energize relay 232. Energization of relay 232 closescontacts 232a to set up vibrator 192 through cam switch 223 and vibratorcontrol 193, and also closes contacts 232b to establish a relay holdingcircuit therethrough.

Cam 220 then acts to close cam switch 227 to energize a solenoid 234which actuates a valve 236 to operate 90 air rotator 178. As rotator 178is operated, the receiver 177 is rotated through arm 179 and link 181 toalign the opening 189 in receiver 177 with passageway 191 and unlatchingmembers 186 186 act on latches 7474 of fixture 31 to unlatch and openthe fixture 31 in the receiver 177.

Shortly after the air rotator 178 is operated, cam 216 closes cam switch223 to actuate vibrator 192 to aid in freeing the core halves 21 and 22from the fixture 31.

Between the operation of air rotator 178 and vibrator 192, the cam 221closes cam switch 228 to energize a solenoid 237 which actuates a value238 to operate air rotator 196, rotating shaft 198 90 in thecounterclockwise direction in relation to FIGS. 10, 11A and 12. As seenin FIG. 11A, the cam slot 20% renders the rotator 198 effective onlyduring its last 45 of rotation wherein the shaft 198 engages pin 206 topivot swing nest 159 45 counterclockwise at an angle to base 172. Atthis time, the pin 207 has rotated 45 clockwise in FIG. 11B and nowengages the opposite edge of cam slot 205. Thereafter cam 222 closes camswitch 229 to energize a solenoid 239 which actuates a valve 241 tooperate air rotator 197. The rotator 197 rotates shaft 199counterclockwise in FIG. 118 to move pin 207 about axis L-L and thusrotate swing nest 159 90 counterclockwise such that at the end of itsmovement swing nest 159 is in the opposite 45 orientation as shown bythe phantom lines of FIG. 12. By now the core halves 21 and 22 shouldhave been freed fromfixture 31 and deposited in discharge chute 161.

Thereafter cam 220 opens cam switch 227, deenergizing solenoid 234 todeactuate valve 236 and operate air rotator 178 90 in the clockwisedirection of FIG. 11, rotating arm 179 and link 181 to rotate receiver177 back into the original position shown in FIGS. and 11.

Finally cam switch 229 is operated by cam 222 to deenergize solenoid 239and deactuate valve 241 to operate air rotator 197 to rotate shaft 19990 clockwise according to FIG. 11B. Cam slot 205 renders shaft 199effective only during the latter 45 of movement thereof to engage pin207 and rotate swing nest 159 counterclockwise from the phantom positionof F 1G. 12 to its original upright position.

The fixture 31 within the nest 159 may be removed by an operator or areturn conveyor may be provided to receive the fixture 31 which may bepushed out of the receiver 177 by a newly arriving fixture 31. Thereturn conveyor may communicate with the fixture conveyor belt 82 torecycle the empty fixture 31.

What is claimed is:

1. In a test apparatus for separable magnetic cores;

a fixture for receiving the separated parts of a magnetic core;

an electromagnetic test facility supported within said fixture andelectrically accessible from without said fixture;

means for inserting the separated parts of the core within said fixtureon axially opposite sides of said test facility;

means for associating said inserted core parts within said fixture toassemble the core in operative relationship with said test facility;

means without said fixture for providing electrical testing access tosaid test facility; and

means for selectively varying the operative relationship of theassembled parts of the core with said test facility to render availablea range of test results.

2. A test apparatus for releasably assembling corresponding halves of ahollow article which comprises:

a contractable means for receiving the corresponding halves of thearticle in spaced axial alignment;

a test facility;

means disposed within said receiving means in the axial space betweenthe article halves for supporting said test facility;

means flexibly mounted to said receiving means in axial alignment withsaid test facility for biasing one of the corresponding halves of thearticle into engagement with said test facility to prevent rotation ofthe one of the corresponding halves of the article;

means rotatably mounted to said receiving means in axial alignment withsaid test facility and said biasing means for engaging and rotating theother half of the article to selectively vary the operative relationshipafter the article is assembled with said test facility to renderavailable a range of test results;

means for contracting said receiving means to assemble the articlebetween said biasing means and said engaging and rotating means toenclose said test facility;

means for releasably retaining said receiving means in said contractedcondition to maintain said article in an assembled state; and

means for releasing said retaining means to permit said contractedreceiving means to expand to permit removal of said article halves.

3. A test apparatus as recited in claim 2, wherein said hollow articleis a toroidal magnetic core and said test facility includes an inductorcoil.

41. A test apparatus for releasably assembling a pair of cupshapedcorresponding halves of a magnetic core, each half having an internalaxial projection extending from a circular base comprising:

contractable means for receiving the corresponding halves of themagnetic core in spaced axial alignment with the projections of eachcore half facing one another;

a test coil bobbin disposed within said receiving means, said bobbinhaving an axis coextensive with the axes of the aligned core halves, forsupporting a test coil;

means for inserting the core halves in said receiving means on axiallyopposite sides of said test coil bobbin;

means for contracting said receiving means to assemble the magnetic corehalves to enclose said coil bobbin with the projections extendingaxially therein;

means for releasably retaining said receiving means in said contractedcondition to maintain the magnetic core halves in the assembled state;

means rotatably supported within said receiving means and frictionallyengaging one of said core halves;

means for driving said rotatably supported means to rotate said engagedcore half; and

means for releasing said retaining means to permit said contractedreceiving means to expand to permit removal of said core halves.

5. A test apparatus as defined in claim 4, further comprismeans disposedwithin said receiving means and operable when said receiving means iscontracted for exerting a predetermined constant axial pressure on saidcore halves while they are maintained in the assembled state.

6. A test fixture for releasably assembling a pair of cupshaped halvesof a hollow toroidal magnetic inductor core which comprises:

a central block;

a test coil bobbin;

means for supporting said bobbin within said central sec tion;

a first end plate connected to one side of said central block andmounted for movement toward and away from said central block;

a first pad supported within said first end aligned with said bobbin;

a second end plate connected to the opposite side of said central blockand mounted for movement toward and away from said central block;

a second pad supported within said second end plate and axially alignedwith said bobbin and said first pad;

spring means for nonnally urging said first and second end plates awayfrom said central block to define a first core half receivingcompartment between said first pad and said bobbin and a second corehalf receiving compartment between said second pad and said bobbin;

means for inserting said core halves in the first and second receivingcompartments, respectively;

means for moving said end plates toward said central block;

and

latching means within said central block for retaining said first andsecond end plates in juxtaposition with said central block when said endplates are moved toward said central block to assemble the core halvesbetween said pads to capture said bobbin.

7. A test fixture as defined in claim 6, wherein:

said first end plate includes a calibrated spring for resiliently urgingsaid first pad toward said second pad with a predetermined force tomaintain a constant pressure on said assembled core halves between saidpads; and

said second pad is mounted for rotation about the axis of said bobbin.

8. A test fixture as defined in claim 7, wherein:

plate and axially said second pad includes means for frictionallyengaging one of said assembled core halves for preventing relativemovement between said frictionally engaged core half and said secondpad.

9. In a testing apparatus for testing separable halves of a magneticinductor core;

a closable test fixture for receiving a pair of core halves, saidfixture comprising a test coil encloseable by said core halves, a pairof test terminals connected to the coil and means for mounting one corehalf for rotation with respect to the other core half;

a loading station;

a closing station;

a testing station;

an unloading station;

detecting means at said loading station for detecting the presence of apair of magnetic inductor core halves therein;

conveyor means responsive to the operation of said detector means forconveying said fixture to said loading station;

means at said loading station for inserting said detected core halvesinto said fixture and for successively conveying said fixture to saidclosing station, said testing station and said unloading station;

means at said closing station for closing said fixture to enclose saidtest coil within said core halves;

means at said test station for making electrical connection to said testterminals of said fixture;

means at said test station for rotating said core half mounting means;and

means at said unloading station for opening said fixture to release saidcore halves.

10. A test apparatus as recited in claim 2, wherein said biasing meansis a spring-biased shaft having a pad mounted on the end engaging theone half of the article.

'11. A test apparatus as recited in claim 10, wherein said engaging androtating means is a rotatably mounted shaft accessible from without saidreceiving means having a friction pad mounted on the end engaging theother half of the article.

12. A test apparatus according to claim 1, further including:

means for disassembling the assembled core to release the separated coreparts.

1. In a test apparatus for separable magnetic cores; a fixture for receiving the separated parts of a magnetic core; an electromagnetic test facility supported within said fixture and electrically accessible from without said fixture; means for inserting the separated parts of the core within said fixture on axially opposite sides of said test facility; means for associating said inserted core parts within said fixture to assemble the core in operative relationship with said test facility; means without said fixture for providing electrical testing access to said test facility; and means for selectively varying the operative relationship of the assembled parts of the core with said test facility to render available a range of test results.
 2. A test apparatus for releasably assembling corresponding halves of a hollow article which comprises: a contractable means for receiving the corresponding halves of the article in spaced axial alignment; a test facility; means disposed within said receiving means in the axial space between the article halves for supporting said test facility; means flexibly mounted to said receiving means in axial alignment with said test facility for biasing one of the corresponding halves of the article into engagement with said test facility to prevent rotation of the one of the corresponding halves of the article; means rotatably mounted to said receiving means in axial alignment with said test facility and said biasing means for engaging and rotating the other half of the article to selectively vary the operative relationship after the article is assembled with said test facility to render available a range of test results; means for contracting said receiving means to assemble the article between said biasing means and said engaging and rotating means to enclose said test facility; means for releasably retaining said receiving means in said contracted condition to maintain said article in an assembled state; and means for releasing said retaining means to permit said contracted receiving means to expand to permit removal of said article halves.
 3. A test apparatus as recited in claim 2, wherein said hollow article is a toroidal magnetic core and said test facility includes an inductor coil.
 4. A test apparatus for releasably assembling a pair of cup-shaped corresponding halves of a magnetic core, each half having an internal axial projection extending from a circular base comprising: contractable means for receiving the corresponding halves of the magnetic core in spaced axial alignment with the projections of each core half facing one another; a test coil bobbin disposed within said receiving means, said bobbin having an axis coextensive with the axes of the aligned core halves, for supporting a test coil; means for inserting the core halves in said receiving means on axially opposite sides of said test coil bobbin; means for contracting said receiving means to assemble the magnetic core halves to enclose said coil bobbin with the projections extending axially therein; means for releasably retaining said receiving means in said contracted condition to maintain the magnetic core halves in the assembled state; means rotatably supported within said receiving means and frictionally engaging one of said core halves; means for driving said rotatably supported means to rotate said engaged core half; and means for releasing said retaining means to permit said contracted receiving means to expand to permit removal of said core halves.
 5. A test apparatus as defined in claim 4, further comprising: means disposed within said receiving means and operable when said receiving means is contracted for exerting a predetermined constant axial pressure on said core halves while they are maintained in the assembled state.
 6. A test fixture for releasably assembling a pair of cup-shaped halves of a hollow toroidal magnetic inductor core which comprises: a central block; A test coil bobbin; means for supporting said bobbin within said central section; a first end plate connected to one side of said central block and mounted for movement toward and away from said central block; a first pad supported within said first end plate and axially aligned with said bobbin; a second end plate connected to the opposite side of said central block and mounted for movement toward and away from said central block; a second pad supported within said second end plate and axially aligned with said bobbin and said first pad; spring means for normally urging said first and second end plates away from said central block to define a first core half receiving compartment between said first pad and said bobbin and a second core half receiving compartment between said second pad and said bobbin; means for inserting said core halves in the first and second receiving compartments, respectively; means for moving said end plates toward said central block; and latching means within said central block for retaining said first and second end plates in juxtaposition with said central block when said end plates are moved toward said central block to assemble the core halves between said pads to capture said bobbin.
 7. A test fixture as defined in claim 6, wherein: said first end plate includes a calibrated spring for resiliently urging said first pad toward said second pad with a predetermined force to maintain a constant pressure on said assembled core halves between said pads; and said second pad is mounted for rotation about the axis of said bobbin.
 8. A test fixture as defined in claim 7, wherein: said second pad includes means for frictionally engaging one of said assembled core halves for preventing relative movement between said frictionally engaged core half and said second pad.
 9. In a testing apparatus for testing separable halves of a magnetic inductor core; a closable test fixture for receiving a pair of core halves, said fixture comprising a test coil encloseable by said core halves, a pair of test terminals connected to the coil and means for mounting one core half for rotation with respect to the other core half; a loading station; a closing station; a testing station; an unloading station; detecting means at said loading station for detecting the presence of a pair of magnetic inductor core halves therein; conveyor means responsive to the operation of said detector means for conveying said fixture to said loading station; means at said loading station for inserting said detected core halves into said fixture and for successively conveying said fixture to said closing station, said testing station and said unloading station; means at said closing station for closing said fixture to enclose said test coil within said core halves; means at said test station for making electrical connection to said test terminals of said fixture; means at said test station for rotating said core half mounting means; and means at said unloading station for opening said fixture to release said core halves.
 10. A test apparatus as recited in claim 2, wherein said biasing means is a spring-biased shaft having a pad mounted on the end engaging the one half of the article.
 11. A test apparatus as recited in claim 10, wherein said engaging and rotating means is a rotatably mounted shaft accessible from without said receiving means having a friction pad mounted on the end engaging the other half of the article.
 12. A test apparatus according to claim 1, further including: means for disassembling the assembled core to release the separated core parts. 